Just a warning to anyone on anti-seizure or mood stabilizing meds. Theanine can seriously fuck you up because it alters glutamate channels that your medication may also be altering.
Not everyone can afford a good doctor, so experimenting on their own might be the only way to fix something. People have been hacking their CPAP machines for awhile even though it could kill them.
I, too, wish to chime in here. I've seen people that are absolute wrecks unless they're on theanine, either alone or as an adjunct therapy. I suspect a surprisingly large number of people just have entirely screwed up glutamate/glutamine cycles, and theanine is an amino analogue of them (makes more sense when you realize the name is l-gamma-glutamylthelyamide).